Episode 7. A Fubuki model Shinki has finally returned to her Mistress' apartment after being lost for over a year. She's hesitant to meet her master, who essentially told her to get lost on account of her clumsiness... And the she rings the doorbell,her Mistress sees her... And instantly picks her up.
The OVA Episode 13. It's a Whole Episode Flashback to how Ann, Lene and Ines got caught up in a scheme to steal a prototype Shinki at the American facility where Ann was having a check-up. Hina turns out to be that prototype; after the situation was resolved, all four had to have their memories of the day erased to protect manufacturer secrets. Thanks to her reset in the previous episode, Hina becomes the first of the four to recover this memory, and she now fondly looks back at how Ann's promise to meet each other again came to pass.
Hina (present day): "I may have been reset, but perhaps it was the events of that day that brought my memories back. The day may come when you will remember it too... but it is good that we could all meet again this way."
A meta situation for the fans of Busou Shinki when Kotobukiya bought the entire license, especially with it's spiritual successors Megami Device and Frame Arms Girls being heavily interchangeable with late-model Shinkis, especially with how the new license holders have made all their money from model kits, and would NEVER abandon them like Konami did. The girls now have dozens of new friends in their successors, and even will be standing alongside them for years to come.